Hydrometer



Oct. 11, 1932. D. HIERGESELL lamolmga Fixed Kay 1, 1931 INVENTOR 24/0 fl/awazsaz.

I W I I I! 7 A TT NE) Patented Oct. 11, 1932 1,882,321

UNITED STATES PATENT. OFFICE mnonmnn.

Application filed Kay 1, 931. Serial No. 534,254.

My invention relates to hydrometers and ter at the completion-f the second stage of its partlcularly to that type of hydrometer manufacture. Fig. 4 is a front view of a which is made of glass and consists of a gradcompleted hydrometer in accordance with Hated stem above a hollow bulb in which a. my invention. Fig. 5 is a section along line 5 ballast material is placed to make the instru- 5 5 of Fig. '2.

ment float upright when placed in a liquid, Referring more particularly to the drawthe density or specific gravityof which is ing, in which similar reference characters Sought to be determined by noting the depth identlfy similar parts in the several views, to which the hydrometer sinks in such liquid. is the hydrometer ballast chamber having 10 The. object of my invention isto provide a' the tubing 11 extending upwardly therefrom an new form of hydrometer which possesses and terminating in the tapered bottom porcertainadvantages over the various types of t on 12, comprising the hydrometer body porhydrometers of the prior art. A more par tion prepared of glass by the glass blower in ticular object of my invention is to provide the usual manner. The tapered bottom pora hydrometer which is so constructed that tion 12 of the chamber 10 is open at its lower 05 its allast portion is lined with metal contip, and when the glass blower has shaped gealed in situ from a suction-introduced and the structure he immerses such tip in a vessubsequently released molten mass metal, sel 13containing a solution 14 of block tin leaving a metal-lined pocket for the recepand asmall percentage of zinc. Ihave found tion of weighted bodies and sealing wax or that a molten solution of about onepound of the like, so that the sealing wax adheres not block tin containing about one ounce of zinc to the glass (as usual) but to the metal linyields a-very satisfactory result in the pracing of the hydrometer bulb. By these means, tlce of my invention.

the permanency of the position of all weight- At the upper end of the stem 11, is attached ing portions in the instrument isgreatly ima rubber tubing 15. After the bottom tip of proved. Furthermore by these means the the hydrometer chamber 10 has been imbod of glass is rendered non-shatterable if mersed in the molten metal, sufficient sucbro en and greatly strengthened and the hytion is applied to the rubber tubing 15 to. 'drometer will resist loosening of the weightsuck a quantit of the molten metal 14 u ed parts'notwithstanding repeated expansion into the cham er 10 to an extent approxiso and contraction of the glass or the weighted mating the upper extremity of the tapered parts, in the course of its utilization in testportion 12. After such an amount of the ing liquids of greatly varying temperatures. molten metal has been drawn into the interior A specific embodiment of my invention is of the chamber 10, suction is discontinued,

illustrated in the accompany ng drawmg 1n the hydrometer is raised and the molten met- 8 wh ch my improved hydromete 18 shown at al permitted to run out from the chamber 10. Vii-110115 g of P k A certain amount of the molten metal 14 re- Same- In 531d drawmg 1,1H1Strates mains deposited on the inner surface of the hydrometer at the first stage of F Process. of lower or tapered portion of the instrument. manufacture after the glass tubing forming The amount of tapering of the portion 12 the body of the hydrometer has been Prepared should be just suflicient to permit the metal by the lass blower and in which figure is shown tfie means used in introducing into the to dmg to the Inner surface thereof and I have found that this result can best be obh drometer chamber the metallic composition f rming a coating for the bottom portion of tamed 1f make the ballast chamber 10 06 the chamber as more fully described herein- P shaped so that P Portloll thereof after. Fig. 2 is a vertical section of the hy- 13 f gradufiuy p oss'sectlondrometer after the completion of the first step der these clrcumstances such a am nt of of its manufacture. Fig. 3 is a front -yiew, h molten metal W111 g qt Inner 1- partly in section, of my lIIlPlOVed hydromeface of the chamber as W111 give such cham- 5 chamber has an irregular inner surface (see Fig. 5) The deposition of such metal on the glass, however, effects a silvering of such glass, the, finish of the metal when viewed from the outside through the glass body of the hydrometer appearing as a highly reflective silvered surface much like a mirror.

Upon completion of this step of depositing an amount of the molten metal on the inner surface of the tapered section 12 of the hydrometer chamber, and after the rubber tu ing 15 is removed from the stem 11 the point or tip at the bottom of the tapered portion 12 is cut off and the end sealed by the glass blower, as shown in section at 17 in Fig. 3.

The hydrometer is then filled through stem 11 with a quantity of shot 18 and sealing wax 19, preferably silver colored, which when melted fills the interstices between the shot and holds it rigidly in place, also forming a coating of wax abovethe bod of shot. The hydrometer is then immerse in a standard solution or other suitable standard test liquid and a plurality of readings marked on a loose paper scale 20. melted, such paper scale is graduated from said readings, and the scale inserted into the stem. The hydrometer is then re-tested in the standard solution, the paper scale glued into proper position in the stem, and

the upper portion of the stem sealed.

The completed hydrometer the appearance as shown in Fig. 4, the bottom or tapered portion of the chamber 10 having a highly reflective mirror finish. It will be noted that in a hydrometer made in accordance with the process just described the metal clinging or adhering to the inner surface of the tapered portion 12 of the glass chamber has a marked strengthening effect on the glass so that the possibility of injury to such glass by its expansion or contraction occasioned by the use of the hydrometer in testing. liquids of greatly varyin temperature is greatly reduced. It will ther noted that the de osition of the-metal on the inner glass s I ace results in a construction which greatly reinforces such glass and makes it non-shatterable in the event that the hydrometer is broken. If the hydrometer is dro ped and the glass broken, the fragments 0 glass will 0 g to the metallic liningv and will be revented from dropping into the solution ing an advantage which is highly desirable when working I the glass surface.

The. wax having been.

will then have with certain solutions or liquids.

That is, the metal furnishes a surface to which the wax or other molten ballast will adhere and to which it will be securely joined, when it is cast in position.

While I have described a specific embodiment of my invention and specific steps in the rocess, it is obvious thatvarious modifications therein, particularly in the sequence of ste sand in the configuration of the parts, may e made without departing from the invention.

I claim:

1. A hydrometer comprising a closed glass tube, the ballast chamber of which is provided through a portion of its interior surface with a metallic lining adhering thereto to form a surface to which the ballast may be joined.

2. A hydrometer comprising a closed glass tube having a ballast chamber the lower portion of which is tapered, the inner surface of said tapered portion having adhering thereto a thin coating of metallic composition and a ballast cast in place upon said coating.

3. A h drometer comprising a closed glass tube having a substantially torpedo shape, the tapered portion of said chamber remote from said stem being rovided with an interior adhering lining 0 a metallic composition to furnish a surface to vhich the ballast may be joined.

4. A hydrometer comprising a closed glass tube having a stem, a scale mounted therein, and a ballast chamber the lower portion of stem and a ballast chamber of which is of tapered-configuration, a portion,

Signed at New York city in the county of New York and State of New York this 29th day of April A. D. 1931.

DAVID HIERGESELL.

A still further feature of 111 new hydrometer is that I obtain a better nd between the glass and the sealing wax through the medium of the metallic coating than can be obtained when. the wax is in direct contact with 

